Design of Switchable and Reconfigurable Semi‐lumped Wideband Bandpass Filter

A switchable single‐wideband (SWB)‐to‐dual‐wideband (DWB) bandpass filter (BPF), which is realized by using lumped switches, is presented in this paper. By alternating the operation modes—ON and OFF—in which the ON mode is achieved by placing the capacitors at the switching spots and the OFF mode is achieved by replacing the capacitors with inductors, DWB‐to‐SWB BPF can be achieved on the same device. In addition, by changing the capacitor values, the center frequency (CF) of the lower passband of DWB BPF can be easily tuned from 1.69 GHz to 2.22 GHz, while the higher passband stays almost unchanged. As an example, an SWB‐to‐DWB BPF is designed, fabricated, and measured. This BPF exhibits good performance including wideband, high isolation, compact size, and ability to switch.